Anti-HLA Antibodies After Bone Regeneration Surgery

Overview

This study evaluates the occurrence of anti-human leukocyte antigen (anti-HLA) antibodies following bone regeneration procedures performed prior to dental implant therapy. Allogeneic bone grafts are widely used in regenerative oral surgery due to their favorable osteoconductive and osteoinductive properties; however, their use may be associated with the development of anti-HLA antibodies, which could potentially influence graft integration and healing. Twenty generally healthy adult patients requiring bone augmentation procedures before implant therapy will be included in the study. Patients will receive either a xenogeneic or allogeneic bone graft material during the regenerative procedure. Additionally, half of the participants will receive adjunctive low-level laser therapy (LLLT) in the postoperative period. Blood samples will be collected before surgery and during follow-up to assess anti-HLA antibody levels. Radiological evaluation using cone-beam computed tomography (CBCT) will be performed to assess bone regeneration. After a healing period of approximately 3-6 months, bone samples will be collected during implant placement and analyzed histologically. The study aims to determine whether bone graft origin and photobiomodulation therapy influence anti-HLA antibody development and the healing of regenerated bone tissue.

Bone regeneration procedures are frequently required before implant-supported prosthetic rehabilitation in patients with insufficient alveolar bone volume. Allogeneic bone graft materials are widely used in oral and maxillofacial surgery because of their favorable osteoconductive properties and biological similarity to human bone. Despite these advantages, concerns have been raised regarding the possible immunological response associated with their use, including the development of anti-human leukocyte antigen (anti-HLA) antibodies. The presence of anti-HLA antibodies has been well documented in large organ and tissue transplantation procedures. However, recent reports suggest that even smaller regenerative procedures involving allogeneic bone grafts may lead to the development of these antibodies. Such immunological reactions may potentially influence graft integration, healing dynamics, and the overall regenerative outcome. The aim of this clinical study is to evaluate changes in anti-HLA antibody levels following bone regeneration procedures and to analyze their potential association with bone healing processes. In addition, the study investigates whether adjunctive photobiomodulation using low-level laser therapy (LLLT) may influence the regenerative process. The study includes twenty generally healthy adult patients who require bone augmentation prior to implant-supported rehabilitation. Patients undergo regenerative procedures involving either xenogeneic or allogeneic bone graft materials. In addition, a subgroup of participants receives postoperative photobiomodulation therapy using a diode laser. Before surgery, patients undergo clinical and radiological evaluation, including cone-beam computed tomography (CBCT), to assess the anatomical conditions and plan the surgical procedure. Blood samples are collected prior to surgery to determine baseline levels of anti-HLA antibodies. During the regenerative procedure, bone graft material is placed in the area of the bone defect under local anesthesia using standard surgical techniques. In patients allocated to photobiomodulation therapy, diode laser irradiation is applied in the postoperative period according to the study protocol. Follow-up evaluation is performed approximately three to six months after the augmentation procedure. At this stage, additional blood samples are collected to assess secondary anti-HLA antibody levels. Radiological examination using CBCT is repeated to evaluate bone regeneration parameters. During implant placement, bone core biopsies are obtained using a trephine drill to allow histological assessment of regenerated bone tissue. Histological analysis includes evaluation of inflammatory cell infiltrates, trabecular bone formation, and bone morphology. The results of this study are expected to improve understanding of the immunological response associated with bone grafting procedures and may contribute to the development of more predictable regenerative treatment strategies in implant dentistry.